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+#LyX 1.1 created this file. For more info see http://www.lyx.org/
+\lyxformat 2.15
+\textclass linuxdoc
+\language default
+\inputencoding latin1
+\fontscheme default
+\graphics default
+\paperfontsize default
+\spacing single 
+\papersize Default
+\paperpackage a4
+\use_geometry 0
+\use_amsmath 0
+\paperorientation portrait
+\secnumdepth 3
+\tocdepth 3
+\paragraph_separation indent
+\defskip medskip
+\quotes_language english
+\quotes_times 2
+\papercolumns 1
+\papersides 1
+\paperpagestyle default
+
+\layout Title
+\added_space_top vfill \added_space_bottom vfill 
+gPhoto2 Camera Library Developer's Guide
+\layout Author
+
+Scott Fritzinger
+\newline 
+2000-07-26
+\newline 
+Revision 1
+\layout Standard
+
+
+\begin_inset LatexCommand \tableofcontents{}
+
+\end_inset 
+
+
+\layout Section
+
+Reverse Engineering the Camera Protocol
+\layout Standard
+
+The most difficult part for most developers is obtaining the transfer protocol.
+ If the OEM's are lucky enough, they will simply provide us with the protocol
+ specifications for their cameras and the drivers will be written at no
+ cost to them.
+ Most OEM's refuse to do so though, citing trade secrets or company policy;
+ this is truly unfortunate in that they have effectively told their own
+ customers who use operating systems other than Windows and the Mac that
+ they don't want their future business and that they aren't valued customer
+ to begin with.
+\layout Standard
+
+When OEM's do not cooperate, the developer is left to determine the protocol
+ him/herself through reverse engineering.
+ 
+\layout Subsection
+
+Sniffing the Protocol
+\layout Standard
+
+What follows are the most common setups for sniffing camera protocol traffic.
+ In all setups, a host computer runs the native camera drivers.; typically,
+ the Windows serial port drivers are used for reverse engineering.
+ The drivers are run through a series of functions that include getting
+ a picture index, downloading thumbnails, download full images, deleting
+ images, camera configuration options, in addition to any other features
+ a camera might have.
+ During these operations, one or more of the following methods are used
+ to capture the communication between the host computer and the camera.
+\layout Subsubsection
+
+Serial Repeater
+\layout Standard
+
+A serial repeater consists of the host computer, a computer used as a repeater,
+ and the camera.
+ The setup is shown in figure .
+\layout Standard
+
+The repeater runs special software which reads data from one serial port,
+ logs the communication, and then outputs the data to the other serial port.
+ Data that is from the host computer to the camera and from the camera to
+ the host computer is logged sequentially in a single log file.
+ Information logged includes hexadecimal data values, direction of the communica
+tion, as well as time stamps for synchronization.
+ An example sniffer to use for this configuration is 
+\begin_inset Quotes eld
+\end_inset 
+
+sersniff
+\begin_inset Quotes erd
+\end_inset 
+
+.
+\layout Subsubsection
+
+
+\begin_inset Quotes eld
+\end_inset 
+
+Y
+\begin_inset Quotes erd
+\end_inset 
+
+ Serial Cable
+\layout Standard
+
+To avoid using two computers, a Y serial cable can be used.
+ The 
+\begin_inset Quotes eld
+\end_inset 
+
+trunk
+\begin_inset Quotes erd
+\end_inset 
+
+ end of the serial cable attaches to the camera's serial transfer cable,
+ while the two 
+\begin_inset Quotes eld
+\end_inset 
+
+branches
+\begin_inset Quotes erd
+\end_inset 
+
+ plug in to two serial ports on the host computer.
+ Figure shows this setup.
+\layout Standard
+
+The camera drivers use one of the serial ports on the host computer, while
+ the other port is opened with a hexadecimal monitor application that dumps
+ all communications on the port to a file.
+ The downside to this approach is the developer would have to determine
+ which sets of data was generated by the camera or the host computer.
+ Also, a Y cable would have to be either built or purchased from an electronics
+ supply store.
+\layout Subsubsection
+
+Virtual Device Driver Hooks
+\layout Standard
+
+The Windows platform allows virtual device drivers to 
+\begin_inset Quotes eld
+\end_inset 
+
+hook
+\begin_inset Quotes erd
+\end_inset 
+
+ into other drivers to provide additional functionality or feature enhancements.
+ A combination GUI and device driver named PortMon by Systems Internals
+ is a communications debugging utility that hooks into the existing Windows
+ serial device driver (vcomm.vxd) and logs communications.
+ Figure shows this equipment arrangement.
+\layout Standard
+
+This setup allows the developer to not use any extra hardware by simply
+ relying on software.
+ This is perhaps the easiest method for capturing camera data.
+\layout Subsection
+
+Making Sense Out of the Protocol
+\layout Standard
+
+What follows are some pointers on decoding camera protocols.
+ It uses a protocol that isn't really any camera protocol in particular,
+ but should demonstrate some commonalities between most camera protocols.
+\layout Enumerate
+
+Cameras like to ping.
+ This is the in the form of an "ACK"" command that is different for different
+ cameras.
+ Basically, it is usually a short packet (probably 1 byte) that is sent
+ both ways in order for the camera to know the computer is there or vice
+ versa.
+ It is also sometimes used to wake up a camera that has gone into power-save
+ mode.
+ It usually starts out the communications, as well as confirms each packet
+ in any sort of "mass" transfer.
+ The opposite, a "NAK", is sent to basically say the last packet was not
+ received, or an error has occured.
+ Again, this is usually just a single byte as well.
+\newline 
+
+\newline 
+Example:
+\newline 
+Computer: 01
+\newline 
+Camera : 01
+\newline 
+
+\newline 
+The Camera sent an ACK ("01") and the Computer responded with an ACK as
+ well.
+\layout Enumerate
+
+Transfers are usually in "reverse network order", meaning least significant
+ bytes come before most significant bytes.
+ For example, 
+\begin_inset Quotes eld
+\end_inset 
+
+00 08
+\begin_inset Quotes erd
+\end_inset 
+
+ should actually be reassembled as 
+\begin_inset Quotes eld
+\end_inset 
+
+08 00
+\begin_inset Quotes erd
+\end_inset 
+
+.
+ 
+\layout Enumerate
+
+Most protocols use starting and stopping bytes.
+ 
+\newline 
+
+\newline 
+Example:
+\newline 
+Computer: 03 50 00 0f e0 04 
+\newline 
+Camera : 03 03 00 3f 03 04 
+\newline 
+Computer: 01 
+\newline 
+
+\newline 
+For this example, notice the packets begin with "03" and end with "04" (don't
+ pay attention to what is between them).
+ Also notice the Computer sent an "ACK" to confirm it got the packet.
+\layout Enumerate
+
+Packets usually have a "command" byte, which tells either the computer or
+ the camera what to do.
+ Let's say you told the software to retrieve the number of pictures, which
+ at the time happened to be "8", and you got the following:
+\newline 
+
+\newline 
+Computer: 03 01 00 00 00 04 
+\newline 
+Camera : 03 01 00 00 08 04 
+\newline 
+Computer: 01
+\newline 
+
+\newline 
+In this example, you notice the "03" and "04" specifying the start and stop
+ of the packet.
+ Also, you notice the second byte in the Computer packet is "01".
+ The camera responds with the above packet, and low and behold, you see
+ the number 8 in the same packet.
+ It would appear, initially, that the second byte is used as a command byte,
+ and that "01" specifies the camera to return the number of pictures.
+ This may very well be right, but don't jump into it yet.
+ Make sure you look at a bunch of similar situations to confirm this.
+ (Again, notice the "ACK" sent by the computer).
+\layout Enumerate
+
+Most protocols have a "data size" byte(s) in data packets.
+ Let's say that you told the camera to retrieve thumbnail 8 and you get
+ the following:
+\newline 
+
+\newline 
+Computer: 03 02 00 00 08 04
+\newline 
+Camera : 03 02 00 0F (15 bytes) 04
+\newline 
+Computer: 01 
+\newline 
+
+\newline 
+OK, here's a brief breakdown of this transaction:
+\newline 
+
+\newline 
+-Looks like the command to retrieve a thumbnail is "02" (2nd byte in the
+ computer packet), and that the byte that is "08" specifies which thumbnail
+ to return.
+\newline 
+-The camera responds with a "02" in the command field, specifying it is
+ returning a thumbnail, and then sends "0F", and 15 bytes of data.
+ 
+\newline 
+-It looks like the byte "0F" specifies how many bytes are after it in the
+ same packet.
+ This is a data size byte.
+ 
+\newline 
+(Note: this is a simplistic example.
+ No thumbnail will only be 15 bytes :) this leads up to the next thing to
+ consider)
+\layout Enumerate
+
+Most protocols have an "order" or "counter" byte.
+ This is used so that, in large data transfers where the picture may be
+ split up into several different packets, the computer knows how to reassemble
+ all the data.
+ The entire thumbnail more than likely will not be contained in a single
+ packet for logistical reasons, so they break up the data into many different
+ packets and give each packet a unique number (or 
+\begin_inset Quotes eld
+\end_inset 
+
+order
+\begin_inset Quotes erd
+\end_inset 
+
+ byte).
+ Let's say you told your camera to return thumbnail 8 (which is, as mentioned,
+ pretty big), and you get the following:
+\newline 
+
+\newline 
+Computer: 02 03 00 00 08 03 
+\newline 
+Camera : 02 03 00 0F (15 bytes) 03 
+\newline 
+Computer: 01
+\newline 
+Camera : 02 03 01 0F (15 bytes) 03 
+\newline 
+Computer: 01
+\newline 
+Camera : 02 03 02 0F (15 bytes) 03
+\newline 
+Computer: 01
+\newline 
+...
+ 5 more packets and ACKs ...
+\newline 
+Camera : 02 03 08 09 (9 bytes) 03
+\newline 
+Computer: 01
+\newline 
+
+\newline 
+You notice that the 3rd byte of each of the camera packets increments with
+ each packet sent from the camera.
+ This looks like it is an order (counter) byte.
+ the computer can then reassemble the data from all the packets in order
+ to reproduce the image.
+\layout Enumerate
+
+Most protocols have some sort of error detection byte(s) at the end of the
+ packet.
+ This is usually a simple checksum (summation of bytes), or a CRC (a somewhat
+ complex algorithm that reduces the probability of mis-diagnosing a packet
+ with errors by magnitudes).
+ These bytes can take into account only the data, or maybe the entire packet
+ excluding those error detection bytes.
+ If this isn't a known scheme, this winds up being the hardest part of reimpleme
+nting the protocol.
+ Lets take the above example again, this time we'll add a couple bytes on
+ the end for error detection:
+\newline 
+
+\newline 
+Computer: 02 03 00 00 08 03
+\newline 
+Camera : 02 03 00 0F (15 bytes) 0f 02 03
+\newline 
+Computer: 01
+\newline 
+Camera : 02 03 01 0F (15 bytes) 0e 00 03
+\newline 
+Computer: 02
+\newline 
+Camera : 02 03 01 0F (15 bytes) fa d0 03
+\newline 
+Computer: 01
+\newline 
+Camera : 02 03 02 0F (15 bytes) fa d0 03
+\newline 
+Computer: 01
+\newline 
+...
+ 5 more packets and ACKs
+\newline 
+Camera : 02 03 08 09 (9 bytes) d7 38 03
+\newline 
+Computer: 01
+\newline 
+
+\newline 
+Notice how the error detection bytes are usually different for each packet.
+ These may be checksums, or CRC's, or something else.
+ Only way to find out really is to try each one, on different combinations
+ of packet parts (data, order byte, command byte, etc...) and see if you get
+ the same thing.
+ Try this on the shorter packets to make life easier.
+\newline 
+
+\newline 
+Look at one more thing that sticks out in this transaction: for packet with
+ order byte 
+\begin_inset Quotes eld
+\end_inset 
+
+01
+\begin_inset Quotes erd
+\end_inset 
+
+, the Computer responded with a "02
+\begin_inset Quotes erd
+\end_inset 
+
+.
+ and the Camera then resent the same packet it just did.
+ This shows that the NAK byte is "02", and this could happen because maybe
+ the error detection bytes didn't match with the data, or maybe something
+ else happened.
+ either way, the camera resent the last packet, and now you know how the
+ camera can recover from transfer errors.
+ If you didn't get the packet you were expecting, send the camera a NAK
+ and it will resend the same packet again.
+\layout Section
+
+Understanding the gPhoto2 Design
+\layout Standard
+
+The gPhoto2 design is the same three-tiered structure that has worked extremely
+ well in the past with other software packages.
+ Here is a listing of the 3 tiers:
+\layout Itemize
+
+the camera library
+\layout Itemize
+
+the I/O library
+\layout Itemize
+
+the front-end
+\layout Itemize
+
+the 
+\begin_inset Quotes eld
+\end_inset 
+
+core
+\begin_inset Quotes erd
+\end_inset 
+
+
+\layout Subsection
+
+Role of the Camera Library
+\layout Standard
+
+The camera library is in charge of talking directly with the camera.
+ The library uses the gPhoto2 Camera API in order to provide a common access-met
+hod for the library itself.
+ Being dynamically linked, the libraries are loaded at run-time depending
+ on the camera model the end-user would like to access.
+ 
+\layout Standard
+
+In order to provide flexilibity with variations in camera design, there
+ are camera 
+\begin_inset Quotes eld
+\end_inset 
+
+abilities
+\begin_inset Quotes erd
+\end_inset 
+
+ which list, well, the abilities of each camera model.
+ Some camera may support serial port connections only, while others may
+ be able to use USB and a serial port.
+ We've run into cameras that don't support thumbnailing on the camera so
+ there is an 
+\begin_inset Quotes eld
+\end_inset 
+
+abilities
+\begin_inset Quotes erd
+\end_inset 
+
+ field to specify whether or not the camera supports thumbnailing.
+ The 
+\begin_inset Quotes eld
+\end_inset 
+
+abilities
+\begin_inset Quotes erd
+\end_inset 
+
+ also list other things such as supported serial transfer speeds, file deletion,
+ and other functionality.
+\layout Standard
+
+The camera libraries only make functions calls to the I/O library and to
+ the gPhoto2 core.
+\layout Standard
+
+There is more information on the specifics of the camera library in section
+ 3 of this document.
+\layout Subsection
+
+Role of the I/O Library
+\layout Standard
+
+The gPhoto2 I/O library is a platform-independent communications library
+ that support serial, parallel, USB, firewire, and network connections.
+ It is a work-in-progress with a constantly expanding list of supported
+ platforms.
+ This library uses the gPhoto2 I/O library API for accessing communications
+ devices.
+ It enumerates the devices available on a system, and provides read/write
+ access.
+\layout Standard
+
+The camera libraries all use the I/O library for communications with the
+ cameras.
+ By doing having all communications go through a single library, the camera
+ libraries become as portable as the I/O library.
+ Porting gPhoto2 to other platforms become extremely easy.
+\layout Standard
+
+There is more information on the specifics of the I/O library in section
+ 3 of this document.
+\layout Subsection
+
+Role of the Front-end
+\layout Standard
+
+The front-end is the application that the user interacts with.
+ It is usually a command-line program, or a graphical point-and-click interface.
+ The front-end talks only with the gPhoto2 core in order to retrieve pictures
+ and perform other functions with the camera.
+\layout Subsection
+
+Role of the gPhoto2 Core
+\layout Standard
+
+The gPhoto2 
+\begin_inset Quotes eld
+\end_inset 
+
+core
+\begin_inset Quotes erd
+\end_inset 
+
+ is the heart of gPhoto2.
+ It provides services to both the camera libraries and the front-ends.
+ Most of the services deal with error-checking and enumeration of devices
+ (cameras, I/O devices, etc...).
+ The core performs validity checking on data passed to/from the front-end
+ or the camera library.
+\layout Standard
+
+You could consider the core a translator/interpreter/spell-checker/army-general
+ in the 
+\begin_inset Quotes eld
+\end_inset 
+
+big picture
+\begin_inset Quotes erd
+\end_inset 
+
+ of gPhoto2.
+ It does the grunt-work and performs the coordination of the other parts.
+\layout Section
+
+Implementing the Library
+\layout Standard
+
+gPhoto2 camera libraries use the gPhoto2 Camera API (CAPI) for implementation.
+ Here is a listing of the CAPI functions: 
+\layout Standard
+
+camera_id 
+\layout Standard
+
+camera_abilities 
+\layout Standard
+
+camera_init 
+\layout Standard
+
+camera_exit
+\layout Standard
+
+camera_folder_list
+\layout Standard
+
+camera_file_list
+\protected_separator 
+
+\layout Standard
+
+camera_file_get
+\layout Standard
+
+camera_file_get_preview
+\layout Standard
+
+camera_file_put 
+\layout Standard
+
+camera_file_delete 
+\layout Standard
+
+camera_config_get
+\layout Standard
+
+camera_config_set
+\layout Standard
+
+camera_capture
+\layout Standard
+
+camera_summary
+\layout Standard
+
+camera_manual
+\layout Standard
+
+camera_about
+\newline 
+
+\layout Standard
+
+Section 3.1 details the purpose of each of these functions, while Section
+ 3.2 discusses how to use the I/O library.
+\layout Subsection
+
+Camera API
+\layout Standard
+
+The CAPI provides the full set of functions for doing various tasks with
+ the camera.
+ All CAPI functions return either GP_OK for succesful execution , or GP_ERROR
+ for a failure of execution
+\layout Standard
+
+What follows is a listing of the functions, including prototypes and data
+ exchange:
+\layout Subsubsection
+
+camera_id
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve the unique id for the camera library.
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_id (CameraText *id); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\layout Standard
+
+CameraText *id : unique string to represent the camera library
+\newline 
+
+\layout Standard
+
+In order to guarantee that only once instance of the camera library is loaded
+ for each instance of the core, the camera library must copy a unique string
+ into the 
+\begin_inset Quotes eld
+\end_inset 
+
+id
+\begin_inset Quotes erd
+\end_inset 
+
+.
+ Please consult the gPhoto developers to determine which string you should
+ use.
+\newline 
+
+\layout Standard
+
+
+\series bold 
+Example:
+\layout Standard
+
+int camera_id(CameraText *id) {
+\layout Standard
+
+strcpy(id->text, 
+\begin_inset Quotes eld
+\end_inset 
+
+my-unique-string
+\begin_inset Quotes erd
+\end_inset 
+
+);
+\layout Standard
+
+return (GP_OK);
+\layout Standard
+
+}
+\layout Subsubsection
+
+camera_abilities
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve the list of supported cameras and the abilities for each camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_abilities (CameraAbilitiesList *list); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Standard
+
+CameraAbilities *abilities : the list of abilities for the supported cameras
+\layout Standard
+
+int *count : the number of 
+\layout Subsubsection
+
+camera_init
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Initialize the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_init (Camera *camera, CameraInit *init); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_exit 
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Close the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_exit (Camera *camera); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_file_list
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+List the files in a particular folder on the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_file_list(Camera *camera, CameraList *list, char *folder); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_folder_list
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+List the subfolders in a particular folder on the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_folder_list(Camera *camera, CameraList *list, char *folder);
+ 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_file_get
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve a file from the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_file_get (Camera *camera, CameraFile *file, char *folder, char
+ *filename); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_file_get_preview
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve a file's preview from the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_file_get_preview (Camera *camera, CameraFile *file, char *folder,
+ char *filename); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_file_put
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Place (upload) a file to the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_file_put (Camera *camera, CameraFile *file, char *folder); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_file_delete
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Delete a file from the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_file_delete (Camera *camera, char *folder, char *filename); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_config_get
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve the configuration window.
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_config_get (Camera *camera, CameraWidget *window); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_config_set
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Set camera configuration
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_config_set (Camera *camera, CameraSetting *setting, int count);
+ 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_capture
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve live data from the camera
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_capture (Camera *camera, CameraFile *file, CameraCaptureInfo
+ *info); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_summary
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve the camera summary information
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_summary (Camera *camera, CameraText *summary); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_manual
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve the camera user's guide (manual)
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_manual (Camera *camera, CameraText *manual); 
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsubsection
+
+camera_about
+\layout Standard
+
+
+\series bold 
+Purpose: 
+\series default 
+Retrieve information about the camera library
+\layout Standard
+
+
+\series bold 
+Prototype: 
+\series default 
+int camera_about (Camera *camera, CameraText *about);
+\layout Standard
+
+
+\series bold 
+Arguments: 
+\series default 
+d
+\layout Subsection
+
+The gPhoto2 I/O Library
+\the_end